As March drew to a close it was very pleasing to look back at all that’s been achieved through the 2009/2010 work party season, by a large number of hard-working volunteers, and highly supportive individuals that work for a variety of government and private organisations. Most of the remaining (known) Duke of Burgundy sites in Sussex are now under active management, although the amount of habitat maintenance or improvement required on each varies greatly. This species now gives such cause for concern that Professor Jeremy Thomas recently wrote ‘it is a moot point whether the High Brown Fritillary or the Duke of Burgundy is the next most probable butterfly to become extinct in the British Isles’. Hopefully we have now got a sufficiently detailed understanding of its autecology to get the management just right for this notoriously tricky species. Below are some images of recent habitat works performed for the benefit of ‘the Duke’, on a number of different sites in Sussex.

Much has been written recently about the disastrous ‘blitzkrieg’ at Straits Enclosure. While the FC were given a thorough ‘roasting’ over the situation here, it’s important to see such an unfortunate event in context. In Sussex I regularly deal with bodies such as Natural England, South Downs Joint Committee, National Trust, Forestry Commission, Sussex Wildlife Trust, West Sussex County Council, several Downland Trusts, Estate owners and farmers, some of which are very close allies of BC. Over a four year period I would say that the success rate in achieving a positive outcome for butterflies and moths is certainly greater than 95%. I think this represents a much higher level of co-operation than was prevalent in the past, as attitudes have changed for the better. Similar work will be going on in all other BC Branches, so if you don’t already do so, please support them with your membership! I know that some of the regular contributors to UKB get involved with winter work parties, and I’m sure they would all agree that you get a great sense of satisfaction from seeing your local patch flourish, assisted by your own labours – as well as keeping fit, without paying exorbitant gym fees!

Dave Brown made a very important point in the Alice Holt thread – in some areas the FC are doing a sterling job, so it’s far from an ‘institutional’ shortcoming. Last spring I joined some BC staff at Denge Wood in Kent, where positive experiences in managing sites in both the North of England and Sussex were used to inform conservation efforts for the Duke of Burgundy here. The BC Denge Wood Project Officer, Fran Thompson, is doing a great job and her ‘management suggestions’ report was adopted in its entirety by local FC staff. I agree with Dave’s views that things are set to improve for the species here, although it might take a few years for the benefits to really kick in. In Sussex the FC are doing valuable work to benefit the Pearl-bordered Fritillary, at places like Rewell Wood and Abbots Wood.

Although we should all ‘kick up a stink’ when things go seriously wrong, it’s in the nature of all ‘media’ that the negative stories get highlighted, often at the near-total expense of the positive. For every ‘bad’ story, there are literally hundreds of ‘good ones’ out there.

I’d like to ‘second’ Lynn’s comments about this fantastic event, held over a number of days in late March at Reading University. Although there were many sad stories of ‘decline’, I was left with a feeling of optimism, as there are so many like-minded people both in the UK and mainland Europe, doing everything within their powers to reverse these worrying trends.

It was a great opportunity to either meet or catch up with some of the ‘big names’ in the world of butterflies, many of whom gave inspirational presentations. In the evenings the campus bar was packed with delegates, exchanging valuable experience over more than a few pints. I’m already looking forward to the next one!

On Saturday April 10th the Sussex Branch held a Recorders Conference at Haywards Heath, attended by 100 delegates. Anyone with an interest in butterflies, that has set foot in Sussex, will know the name Michael Blencowe – a legend in his own lunchtime (lunchtimes being quite important to Michael). However, it was his equally hard-working partner, Clare Jeffers, who was the star of this show. Ably assisted by other members of the committee, she put together a fantastic event, designed to both enthuse a new army of butterfly recorders, and launch a five year project to culminate in the production of ‘An Atlas of Sussex Butterflies’.

Supported by an Opal (Lottery) grant, there was a lavish spread (including fancy cakes) and no detail had been missed – even down to the provision of sherbet lemons on each table!

Michael gave a talk on the currently-known distribution of the 45 (possibly 46!) species in Sussex, followed by Clare’s summary of the ‘nitty-gritty’ of recording techniques. Crispin Holloway gave an excellent presentation on the changing fortunes of the Silver-spotted Skipper – a ‘climate change winner’. Tom Ottley gave a very informative talk on how to differentiate Small and Essex Skipper (one only has to look at UKB later in the summer to realise how problematic this issue continues to be!).

Apart from performing ‘MC’ duties with more panache than Dale Winton (well, perhaps not a good comparison) yours truly spoke about how to survey for some of our more elusive species; how to locate potentially good habitat for ‘Dukes’ (and other difficult habitat specialists) using ‘remote sensing’; and how some recording techniques (single species timed counts) feed more directly into conservation efforts, by assessing the effectiveness of ongoing habitat management.

It was nice to see a few UKB faces there, together with friends from adjacent counties. Congratulations to Clare & Co.

This week saw the distribution, to Branch members, of Issue 2 of our new-style, all-colour, Annual Report. At 44 pages, and containing many interesting articles, the cover price of £2 to non-members represents much cheapness. Amongst other things, there is a lengthy article on the Queen of Spain Fritillary in Sussex. This subject was also covered (a different paper) in the latest edition of ‘Atropos’. I’ll bring some copies along to the UKB photographic workshop. All proceeds go towards the ‘saving butterflies in Sussex’ fund.

On 13th April I gave my new camera, the Panasonic Lumix FZ38, its first test drive. In some woods near Arundel I found my first two Green-veined Whites of the year. This is one site where recent habitat management work for the Duke of Burgundy really does look like ‘doing the bizz’. When first discovered two years back, a small population was hemmed-in to a small area of greatly overgrown habitat, with nowhere to move on to. A two hour search failed to find a single food plant! A huge area of habitat has now been opened up and I was delighted to see vast quantities of both cowslip and primrose.

I later moved on to Mill Hill at Shoreham, where I saw my first Grizzled Skipper of the year on the 6th April. Numbers had built quite nicely and I was fortunate enough to see a mating pair. I’m definitely ‘very pleased’ with the FZ38.

On Thursday 15th April I returned to Mill Hill with my brother and his family, visiting from Antwerp. Double figure numbers of Grizzled Skippers have now been joined by the first Dingy Skippers of the year, although I failed to get a decent shot of this species. With a NE wind continuing to blow hard, the SW-facing lower slope is providing a really warm and sheltered area at the moment. A good number of Small Tortoiseshells are present here, supporting the observation made by many others, that the species may be making a ‘comeback’ this season – let’s hope so!

It's great to see so many Small Tortoiseshells around this year and, like many others in the South, I'm seeing them in numbers (and locations) that I haven't done so for many years.

In response to some of the questions posed by Lee Hurrell (Sightings - 'Small Tortoiseshells' thread) - there may be a numbers of factors at work here Lee.

Firstly, an explanation of your observation of 'a higher number of STs this spring than can be explained by the apparently lower numbers seen late last autumn'. The post-hibernator butterflies emerge in spring, mate, and their offspring are around through June, July and August. These butterflies mate and give rise to another emergence of adults, which are on the wing through late summer and autumn. Soon after these second brood adults start emerging (which may be over a quite prolonged period of several months), some individuals start tucking themselves away, well in advance of late autumn/winter, and largely un-noticed. So their 'disappearance' from the countryside is a greatly staggered event, with a relatively modest number being active and on the wing at any given time from late August onwards. This phenomenon can also be 'exaggerated' by the fact that we are now seeing a partial third brood of STs in the South, meaning an additional but small emergence of adults very late in the year. Also, (particularly further North and following long, hard winters such as 08/09 and 09/10) a few of the adults that emerge in mid summer (first brood) go straight into hibernation, rather than mate 'this' year. This is a good survival strategy at species level, in the same way that a small percentage of pupae of other species will 'hold back' from emerging until the following year - a little bit of 'insurance' against particularly poor years.

Whereas the STs from a 'previous' year have gone into hibernation over a very prolonged timeframe, when spring arrives they all emerge over a very short period - and are all on the wing at the same time. So this gives the impression of a much higher number than could be explained by the numbers seen at any given time through the preceding late summer/autumn. The same effect can often be seen with Peacocks, which start to tuck themselves away in August. With fewer species around in the spring, we also tend to notice these particular butterflies more. If over-winter survival rates are particularly high (my second point), the whole effect becomes even more obvious.

The over-winter survival rate of STs (and other species) is undoubtedly high this year. This will have been helped by the cold weather, which reduces losses through moulds, parasites, pathogens and some predators. The situation with ST may be even more complex. Although research into the effects of the parasitoid Sturmia bella is ongoing (see photo of a project 'release'), and Owen Lewis' team is yet to make a 'final judgement', this tachinid does seem to have exacerbated the decline of the species. We still don't know the over-wintering strategy of the fly, but being a 'warm climate invader', it might not have thought very much of the cold 08/09 winter! With the 09/10 winter being even colder, we might be seeing an 'upward spiral' and I'm optimistic that numbers might be even higher next year, perhaps returning to the level that many of us have not experienced since our youth!

However, in the longer-term, it is possible that S. bella might start developing a tolerance to colder winters, and we might have a long re-run of warmer, damper winters. This might result in another 'crash' in the future. This cyclicity has always, and will always, affect the fortunes of some of our butterflies.

Hi Neil I was at Mill Hill on Thursday so I must have seen you but not realised it was you and your relatives . I visited Ouse Estuary NR on Saturday , Peacock , Small T , Comma , Large W , Green V White and possibly Small W seen . When if at all would you expect any Clouded Yellows to emerge ? Cheers Mark

Hi Mark,I'm sure we'll 'locate' each other sometime this season! Unfortunately I doubt that any Clouded Yellows made it through that winter. Bearing in mind the area has been thoroughly searched, it would also appear that no Queen of Spain Fritillaries over-wintered in the adult stage at Chichester. If eggs or larvae got through, I would expect to see adults in late June/early July.Neil

During a brief stop at Mill Hill this afternoon, it soon became evident that Dingy Skipper numbers have started to build. Plenty of dogfights going on with the now numerous Grizzled Skippers - mainly on the lower slopes, far end. Good numbers of post-hibernators too.

Sussex Kipper wrote:Bearing in mind the area has been thoroughly searched, it would also appear that no Queen of Spain Fritillaries over-wintered in the adult stage at Chichester. If eggs or larvae got through, I would expect to see adults in late June/early July.

Is there no possibility of pupae having survived? This is a common hibernation stage (my adult hibernators in the Rhône Valley are the exception, rather than the rule) and leads to emergence in April/May in much of France. Tim Cowles, in Lyon, has yet to see his first Queens this year, making it the latest year in his recording history - and I would expect Chichester to be later than Lyon.

Sorry to interrupt the flow of your diary - but it's your fault for making it so interesting. I'm particularly interested in your Queens, a butterfly I always wanted to see when I lived in England and would make a point of visiting if they did set up in Sussex.